<!DOCTYPE html>
<html lang="ch">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>
    for(i=1900;i<=2000;i++){
        year=i;
        if(year%400==0||(year%4==0&&year%100!=0)){
            console.log(year);
        }

    }
</script>